I've just stumbled across the High/Low labels feature
of the contouring resources (great stuff!) but have
an unanswered question: is it possible to limit the
number of High/Low labels to just one per plot? I'd
be quite happy to only have one 'H' and one 'L' in
each plot and have ncl ignore the other relative
maxima/minima.

The labeling feature works fine most of the time, at
least for my data, but I have lots of examples where
a bit more control over how many labels appear would
be a really nice feature.